在完成预处理之后，可以通过调用Input

After you are done with pre-processing, You can add the tensor as input layer by calling tensor param of Input

所以在您的情况下:

tf_embedding_input = ...    # pre-processing output tensor

# Keras model
model = Sequential()
model.add(Input(tensor=tf_embedding_input)) 
model.add(Embedding(max_features, 128, input_length=maxlen))